The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 18, 1991
Filed:
Aug. 13, 1987
David T Wilson, Billerica, MA (US);
Roger H Tancrell, Cambridge, MA (US);
Raytheon Company, Lexington, MA (US);
Abstract
A sheet of polymer material is secured between a pair of clamping members. The sheet is directed through a localized heated region to provide a localized heated portion of said sheet. A first one of said clamping members is pulled away from the second clamping members to stretch said sheet and create from the localized heated portion of said sheet a neck-down region. The neck-down region separates providing a pair of neck-down region portions and a reduced thickness portion or stretched portion of the sheet between said neck-down region portions. One of said neck-down regions propagates along unstretched portions of the sheet as the movable clamping member moves away from the fixed clamping member while the other neck-down region remains adjacent the fixed member. This propagating neck-down region portion of the sheet is kept within the localized heated region by moving the localized heated region at a rate related to the rate which unstretched material of the sheet is fed into the neck-down region portion. While the neck-down region portion is maintained within the localized heated region, an electric field is applied to the neck-down region portion to polarize the film.